2- stroke engine vs 4- stroke engine.

Are you looking to buy a new vehicle but do not know what to choose between a 2- stroke or a 4- stroke engine?

We will help you understand the differences between these two engines and how they work, so that you can appreciate the pros and cons for each.


2- Stroke Engines

Firslty, 2- stroke engines were the most used during the last decade, and up to early 2000s.

How do they work? Here’s an explanation:

You must know that 2- stroke engines utilize a mixture of oil and fuel in order to function.

The engine is activated by a specific cycle, which is the same for a 2- stroke and a 4- stroke engine:

  1. Induction
  2. Compression
  3. Power
  4. Exhaust
Man riding 2- stroke engine snowmobile in the middle of the forest.

A 2- stroke engine gets its name from the fact that the piston undertaking the two stroke motion goes up and then down in order to accomplish a full cycle. So the crankshaft rotates once, when the piston goes up and down, and to fire the spark plug. The two “stroke” in a 2- stroke engine really refers to the movement of the piston.

It is a very efficient and reactive operation. Today, this technology is still used given how light the engine is and the optimal power-to-weight ratio it offers.

The main advantage of a 2- stroke engine is how performant it is, and also –or mostly- how reactive and light it is. This is definitely an engine that will get your adrenaline going during accelerations!

However, the downside is that it is louder and requires more fuel.

4- Stroke Engines

The Polaris Titan Prostar 4- stroke snowmobile.

4- stroke engines are generally preferred by manufacturers as standard offered engines, especially since early 2000. Although the combustion cycle is the same as for the 2- stroke engine, they operate very differently.

Firstly, you may have understood that the 4- stroke engine requires two up-and-down piston cycles to complete a full combustion cycle. This means that the spark plugs will be fired once for every two crankshaft rotations.

The mechanics are also more complex, like by adding, for example, a camshaft and valves. This system provides you with a better energy efficiency, although it is less reactive when you are driving. That is normal, given that the cycle takes longer!

A 4- stroke engine also requires two separate tanks: one for the oil and one for fuel, just like with a car. Instead of mixing oil and gas, it relies on a lubrication system.

The advantages offered by this type of engine are mostly found in the fact that it requires less fuel and also wears down less quickly, because of how it operates.

The Differences Between a 2- Stroke and 4- Stroke Engine

In short, 2- stroke and 4- stroke engines present differences that are worth keeping in mind. Although the 2- stroke engine is more reactive, lighter and more performant, it also wears down faster.

In the case of the 4- stroke engine, it is exactly the opposite: it is less reactive given the slower way in which it operates and given its added weight, which is due to the extra tank, camshaft and valves. However, it is definitely more durable and energy efficient than the 2- stroke. In the long run, it is the most economical option of the two.

As we have mentioned above, the 2- stroke engine functions on a mixture of oil and fuel while the 4- stroke relies on an independent lubrication system. Should you opt for the 2- stroke engine, you will have to check your oil levels regularly so as to ensure that you are maintaining the correct proportions.

Are you still wondering which is best between a 2- stroke and 4- stroke engine? The short answer is that it depends on your preferences. You should, however, take note that several renowned manufacturers have developed excellent options in both categories.

What types of 2S and 4S snowmobiles do we offer at SM Sport?

Are you looking for a good snowmobile, either 2- stroke or 4- stroke? SM Sport has several performant options for you.

Amongst the 4- stroke options we have in stock, you will find the very popular Yamaha Sidewinder and its several different trims, like the RTX, LTX and SR Viper, or even the SRX LE, which has been named the fastest in the world!

Side view of a 4- stroke engine Yamaha Sidewinder snowmobile.
Front 3/4 view of a Polaris snowmobile from the 2- stroke RMK models.

You will also find several performant 2- stroke snowmobiles with Polaris, like with the Patriot 650 or 850 engines, found on the RMK, Switchback and Indy models. Polaris has also developed excellent 4- stroke engines, like the all-new Prostar 4 S, that you will find on the Indy Adventure 900, amongst others.

With 2- stroke engines, you will find several models like the Arctic Cat Mountain Cat and the Yamaha Mountain Max, which are both excellent off-track options, and many more.

With SM Sport, you will be spoilt for choice no matter what type of engine you prefer! Take a look at all of our snowmobiles for sale in the Quebec area, and do not hesitate to ask us for more advice.